r.stats.quantile
Compute category quantiles using two passes.
r.stats.quantile [-rpt] base=name cover=name [quantiles=integer] [percentiles=float [,float,...]] [bins=integer] [output=name [,name,...]] [file=name] [separator=character] [--overwrite] [--verbose] [--quiet] [--qq] [--ui]
Example:
r.stats.quantile base=name cover=name
grass.script.run_command("r.stats.quantile", base, cover, quantiles=None, percentiles=50, bins=1000, output=None, file=None, separator=":", flags=None, overwrite=False, verbose=False, quiet=False, superquiet=False)
Example:
gs.run_command("r.stats.quantile", base="name", cover="name")
Parameters
base=name [required]
Name of base raster map
cover=name [required]
Name of cover raster map
quantiles=integer
Number of quantiles
percentiles=float [,float,...]
List of percentiles
Default: 50
bins=integer
Number of bins to use
Default: 1000
output=name [,name,...]
Resultant raster map(s)
file=name
Name for output file (if omitted or "-" output to stdout)
separator=character
Field separator
Special characters: pipe, comma, space, tab, newline
Default: :
-r
Create reclass map with statistics as category labels
-p
Do not create output maps; just print statistics
-t
Print statistics in table format
--overwrite
Allow output files to overwrite existing files
--help
Print usage summary
--verbose
Verbose module output
--quiet
Quiet module output
--qq
Very quiet module output
--ui
Force launching GUI dialog
base : str, required
Name of base raster map
Used as: input, raster, name
cover : str, required
Name of cover raster map
Used as: input, raster, name
quantiles : int, optional
Number of quantiles
percentiles : float | list[float] | str, optional
List of percentiles
Default: 50
bins : int, optional
Number of bins to use
Default: 1000
output : str | list[str], optional
Resultant raster map(s)
Used as: output, raster, name
file : str, optional
Name for output file (if omitted or "-" output to stdout)
Used as: output, file, name
separator : str, optional
Field separator
Special characters: pipe, comma, space, tab, newline
Used as: input, separator, character
Default: :
flags : str, optional
Allowed values: r, p, t
r
Create reclass map with statistics as category labels
p
Do not create output maps; just print statistics
t
Print statistics in table format
overwrite: bool, optional
Allow output files to overwrite existing files
Default: False
verbose: bool, optional
Verbose module output
Default: False
quiet: bool, optional
Quiet module output
Default: False
superquiet: bool, optional
Very quiet module output
Default: False
DESCRIPTION
r.stats.quantile is a tool to analyse exploratory statistics of a floating-point "cover layer" according to how it intersects with objects in a "base layer". It provides quantile calculations as selected "zonal statistics".
NOTES
r.stats.quantile is intended to be a partial replacement for r.statistics, with support for floating-point cover maps. It provides quantile calculations, which are absent from r.stats.zonal.
Quantiles are calculated following algorithm 7 from Hyndman and Fan (1996), which is also the default in R and numpy.
EXAMPLE
In this example, the raster polygon map zipcodes
in the North Carolina
sample dataset is used to calculate quantile raster statistics using the
elevation
raster map:
g.region raster=zipcodes -p
# print quantiles
r.stats.quantile base=zipcodes cover=elevation quantiles=3 -p
27511:0:33.333333:134.717392
27511:1:66.666667:143.985723
27513:0:33.333333:140.669993
27513:1:66.666667:146.279449
27518:0:33.333333:115.140101
27518:1:66.666667:129.893723
[...]
# write out percentile raster maps
r.stats.quantile base=zipcodes cover=elevation percentiles=25,50,75 \
output=zipcodes_elev_q25,zipcodes_elev_q50,zipcodes_elev_q75
REFERENCES
- Hyndman and Fan (1996) Sample Quantiles in Statistical Packages, American Statistician. American Statistical Association. 50 (4): 361-365. DOI: 10.2307/2684934
- Engineering Statistics Handbook: Percentile, NIST
SEE ALSO
r.quantile, r.stats.zonal, r.statistics
AUTHORS
Glynn Clements
Markus Metz
SOURCE CODE
Available at: r.stats.quantile source code
(history)
Latest change: Friday Feb 07 19:16:09 2025 in commit a82a39f